The present invention relates to a new and improved metallurgical vessel for high-melting alloys, especially alloys formed on the basis of nickel, steel or the like.
In its more particular aspects, the present invention relates to a new and improved metallurgical vessel for high-melting alloys, especially alloys formed on the basis of nickel, steel or the like, in which molten metal is caused to solidify under the action of electric direct-current or electric alternating-current.
To obtain a grain structure which is as homogeneous as possible during ingot and strand casting it is already known to permit the molten metal to solidify under the action of the electromagnetic fields of a number of solenoids. Such solenoids are interdependently supplied with electric direct-current or alternating-current so that, for example, travelling fields or the like are generated whereby the melt is made to move relative to the mold. The solenoids may be arranged such as to rotate the melt about the longitudinal axis of the mold or such that the melt flows in axial direction and returns again in the opposite direction.
It is also known to arrange stirring coils in metallurgical furnaces which are operated by alternating-current or direct-current. The electromagnetic field generated by such stirring coils is superimposed on the electromagnetic field caused by the current for the melting operation.
As already stated, the current producing the melting work builds up an electromagnetic field which also may affect the solidification of the melt. If an asymmetric electromagnetic field is built up relative to the mold, then the solidifying melt is differently displaced, and thus, also differently cooled depending in which region the melt is located. It should be considered that in a mold, particularly when heat is generated and a metal melt is possibly additionally charged, at least heat-caused flows or streams occur during the solidification of the melt and these flows or streams of the melt are then deflected by an asymmetric magnetic field. Such asymmetric magnetic fields, for example, can occur during electroslag remelting. It is not required for such operation that the entire electrode block has to be remolten, but there can also be initially introduced a melt into the mold and only the so-called crop-heating-process can then be carried out using an electrode. The aforementioned asymmetric magnetic fields can also occur in an electric arc-furnace and the like.